For the Good of the Case
by 13.shimer.13
Summary: Sherlock meddles with Joan's love life for the good of the case, with an interesting outcome. Currently marked as complete, would consider writing more if people wanted.
1. Rising Tensions

"WATSON!" from the shower, she heard his dulcet tones and sighed, admitting defeat. Sherlock was always abruptly ruining her peace and quiet. Grumbling, Joan Watson grabbed and wrapped her fluffy towel around herself, securing it tightly and then reaching for a second towel, which she dried her hair with and then made a turban with.

"COMING!" she was annoyed and flushed from the hot water. She checked the time. Eight minutes since she had gotten into the shower. _Eight _minutes_._ She scowled, but rushed downstairs to see what was so important. They had been working on a case; perhaps he had made some headway with it. "What is it?" she called as she walked down the stairs quickly, still wearing nothing but her towel. If it was so important he chose to disrupt her shower, then she knew she had better get down there quickly. A little doubt flickered in her mind—this was Sherlock after all. He could just as easily have disrupted her shower to ask her to make him some coffee, as to solve a case with her.

"Ah, Watson." He looked up, seemingly finding nothing peculiar about her wearing only two towels. She opened her mouth to ask him what was going on, but he interrupted her before she could. "Glad you could make it so promptly, hope I wasn't disturbing you?" she tried to talk again, to no avail. "Excellent. This won't take two minutes. I just wanted to inform you that I've arranged a date for you tonight, so put something nice on and be ready to go in—" he paused to check his watch "—half an hour."

"What? Why?" Joan's eyes widened as she surveyed her friend, wondering silently what she had ever done to be chosen for his sober companion, and questioning her own sanity for staying as his partner once the six weeks had ended.

"It's important for the case," he told her, looking back down at the case files in front of him. She spluttered, and almost dropped her towel in shock.

"The case? How could a date be important for the case?" her stern voice made him look up and smile slightly.

"You're not very frightening in a towel, Watson," she glared, and stood her ground.

"I'm not being set up by _you,_ Sherlock. I have enough friends trying to do that for me. I'm not interested. I also don't see how my love life could _possibly_ be interlinked with the case. Are you setting me up on a date with the murderer, to try and get him to confess?"

"No, of course not—though that's not a bad idea. We'll save it for another day. My dear Watson, your love life, if that's what you want to call it, is intrinsically tied to the case, as is mine. Coitus, as you should be aware by now, helps the body and mind to relax. We are both entirely too tense to be completely focused on the case and, to be vulgar, you need to get laid." he stood up, staring directly into her eyes.

"How long has it been, Watson? You certainly haven't been 'getting any' while you've been working with me, and you've gone on some dates; dinner with Ty, coffee with the married man. You're not the type for a one night stand, need to establish some sort of connection with someone before hand. Which is why Detective Bell is taking you out tonight," he informed her. Sherlock took her hand and lead her upstairs, knowing that she would have to use her other hand to hold her towel up and had to choose between her modesty and escape.

"_Detective Bell_? You've set me up with Detective Bell?"

"You are both unattached, Watson, and he is attracted to you. I asked him as much while I was setting you up. You already have a connection, you're friends. This sort of date would be mutually beneficial to both of you," he explained. By this point they were in her bedroom, and she was still scowling and holding her towel around her, shivering. She wished wholeheartedly she had carried on showering, ignored him, gotten dressed into comfortable clothing at a leisurely pace and then left for a jog, some food, a visit to friends or family... anything other than being in this situation, holding a towel around her while her meddling friend selected a plain red dress and some black leggings. He threw a cute cardigan onto the bed, then began rooting around her undergarments.

"_Sherlock,_" he had taken it too far. "I've had enough, what are you doing?! You can't just arrange a date for me with Detective Bell, and pick out my clothes and look through my underwear—"

He chucked a lacy black bra and matching panties onto her bed, muttering "Yes, this should do nicely,"

"—and interrupt my shower by yelling like something terrible was happening, all in some sort of misguided attempt to help the case! Do you know how long my shower was? _Do you_? Eight minutes, Sherlock, _eight_ minutes! If I am tense, it's because of you, not my lack of sex! Who said I hadn't had sex, anyway?"

"Your gait, need I remind you, says it all. Now get dressed. I'm assuming you'll want to work on your mood before Bell gets here." Breathing heavily, Joan put her hands on her hips.

"Like _hell_ am I getting changed with you in here, and like _hell_ am I going to be in a good mood when Bell gets here!" Sherlock sighed.

"Really, Watson. Stop being so tiresome. Your towel fell while you were yelling at me, in case it had slipped your attention. It hadn't slipped mine," he added slyly, expecting her to be mortified.

She was, but she glared at him while she picked the towel up, self conscious, but determined to defy him. He expected her to meekly reach for the clothes he had had the gall to pick out—she would show him.

Sherlock cleared his throat. "Yes, well. Proceed dressing, Watson." she hadn't heard him talk like this before, huskier than usual. And she had never seen his face so intense; they were unable to look away from each other. She hadn't even wrapped the towel around her, too busy looking into his eyes. He cleared his throat again, but they carried on staring into each others eyes. The silence was becoming uncomfortable.

"You... you know, Watson. Perhaps you needn't go with Detective Bell after all," his voice was slightly strangled. "Incredibly rude of me to set you up without even asking, I realise that now. It's just—the case—the release would help, wouldn't it?" Joan wondered when he would stop staring at her, but found that she didn't mind it. She made no move to pull the towel around her, holding it limply by her side and biting her lip.

He inched slightly closer to her, biting his own lip. "Perhaps you should stay in tonight, with me. I confess that I'm getting very, _very _turned on right now. Your body is quite... phenomenal. And we can—if we—that is to say, why waste time going out to dinner and back to Bell's, and then here again to work on the case? We can very easily remedy your predicament here, save time, coitus together so to speak... straight on with the case afterwards..." Joan's eyebrows rose.

"Babbling, Holmes? I never thought I'd see the day where you were reduced to babbling,"

"It wouldn't change anything," he said. Joan was relived that he sounded slightly more normal. "between us, that is. If we had sex it would be for the good of the case. Both of us fully focused on the case, renewed energies and all."

Joan's brain was screaming at her, one part rationalising that it _had_ been a while since she had had sex, and that with Sherlock she had no doubt that they could go back to being partners, no messy relationship involved. On the other hand, he was her friend—her best friend. But she was naked, and he was attractive, and her good friend. He clearly was getting turned on, she noticed. He used to play the violin, she reminded herself, and that did it. Joan nodded.


	2. Compatibility

Disclaimer: I don't own the characters, Elementary writers do. This story seems to be going somewhere, I already have an idea for the third chapter. Please review, hope you enjoy.

Of course, it was one thing for two room-mates and best friends to decide they wanted to have sex with one another, and an entirely different matter to carry the act out. Joan slipped the lacy bra and panties on quickly, followed by the light red dress and leggings. If they were going to have a conversation about this, a proper, rational conversation then she wanted to be on equal footing with him.

"You are... putting clothes on?" he was bemused. "I thought the point was to take them off."

"Yeah, together. After we've talked about it."

"What's left to talk about? I thought we had talked about it, just now. And you nodded, yes? Watson—the sooner we've completed this, the sooner the case will be solved."

"No, we need to talk about it still. Aren't there rules for this sort of thing? We're... friends, Sherlock. And room-mates. And we work together."

"Yes." he raised his eyebrows, a classic 'so what?' look. "I don't see how adding sex to that list of things we do together will change anything," he shrugged. Joan sighed and sat down on her bed.

"Sex has a tendency of changing things," she pointed out wryly. "what if we're wrong and it does change things between us?" Sherlock sat opposite her on the bed. They were both cross-legged, and nearly touching.

"Look... Joan. Your companionship, it means a lot to me. It's very valuable, and I would be a fool, the biggest fool, to chuck that away. Sex is, in this instance, a means of gratification and a solution to tension. I work better after sex; perhaps you will find it helpful too. If not, then we won't do it again. This is just for the good of the case."

"For the good of the case," Joan repeated, her resolve strengthening. They were really going to do this. "Okay, umm, so if we just uh—" she leaned forward, forgetting what she wanted to say as she looked into his eyes. They were rather distracting this close up.

Sherlock simply nodded, and their lips met. It was a soft, warm kiss. It ended entirely too soon.

"How was that?" Sherlock asked her. Joan almost laughed at how nervous he looked; afraid that he had moved too soon.

"Let's try it again," she said, feeling oddly shy around his new facet. Detective Sherlock, friend Sherlock and room-mate Sherlock she knew like the back of her hand. This new, non-platonic Sherlock was completely unexpected.

"You sure?" He looked like a guilty schoolboy, and it reassured her. They could do this. It would be fine.

"Yes, Sherlock." Joan smiled.

"Absolutely, positively sure?" he asked, his eyes searching hers until he seemed to find what he was looking for.

"Just shut up and kiss me," she commanded, moving closer to him. He did. Their tongues caressing, Sherlock tentatively put an arm around Joan. It was clear that he wasn't going to take it much further unless she proved to him that she was completely comfortable. She uncrossed her legs and enveloped his waist with them, scooting up so that she was hugging him, kissing him, practically straddling him. He finally began to respond, to Joan's delight. Their chests were pressed together, their hands exploring each other's back's, tugging hair. While they kissed, Joan wriggled around to get more comfortable.

"Did you just moan?"

"Well your ah... adjustment, Watson." she noticed that his voice was sounding strangled once again and smiled. She wriggled once more, this time maintaining eye contact, and was rewarded with a groan. They kissed, Joan unbuttoning his waistcoat and chucking it on the floor. Underneath he wore the top he had worn the first time they had met, which said "I am not lucky I am good". It was quickly discarded. She had seen him topless before, but this time she got to touch him, running her hands over his tattoos.

"Mm, be a love and lift up a bit so I can get your dress and leggings off?"

"I will if you get your pants off." they stood to remove their respective clothing, but soon resumed making out.

"Condom?" Joan asked, lightly scratching his back.

"Your bag."

"I don't remember putting a condom in my bag."

"You didn't. My dear Watson, I was sending you out to get laid tonight, _not_ impregnated. I thought Bell probably had condoms at his, but, well. Better safe than sorry. Quite convenient now, isn't it?" he licked his lips and she nodded, bending down to get the condom. While she was bent over, rooting around in her bag, Sherlock reached over and unsnapped her bra and pulled her pantiess down part way. While his voice had been rough, his hands were gentle as he massaged the back of her thighs. She pulled off her bra and straightened up. Her panties fell down and she stepped out of them, smiling at Sherlock, who had taken his boxers off and was reaching for the condom.

"Quick question Wat—Joan. Which position do you prefer? And would you rather I call you Joan or Watson while we do this? Screaming 'Watson' during climax is a little cold, isn't it?"

"Joan will do fine for this. I like being on top, if that's okay with you?"

"_Okay_?" he grinned. "That works just fine for me. Perfectly, even. Good to know that we're compatible."

"I'm glad." Joan blushed slightly, then pushed him onto the bed with a laugh. Sherlock smiled while he pulled the condom out of the packet and slid it onto his erect penis. She bit her lip; was this really happening?

"Come on, love," he patted his left thigh, a clear invitation for her to climb onto him. It was the first time he had ever called her anything other than Watson or Joan, to her knowledge; she liked it.

"Coming," she said.

"You will be soon," he retorted, with a mischievous smirk.


	3. Discovery

Disclaimer: Still don't own Elementary. Note: reviews would be appreciated! They encourage me to write more, also what do you think of where this is going?

Detective Bell had prepared for the date; he groomed himself, listened to the radio, and tried not to think about it too much. To say that Joan Watson was an amazing woman would be an understatement. She was clever, good looking, funny... and going out on a date with him, apparently.

The way Sherlock had pitched the date to him was like this: he had cornered Bell in the police station, quietly asking,"Have you ever thought about having sex with Watson?"

"...No?"

"Don't deny it. The panic in your eyes, Watson's physique, and your sexual orientation would suggest otherwise. It's not a bad thing, Bell. It will help. I am setting you up on a date with her, on which there is a good chance that the two of you will have sex."

"What? Why?"

"It's an experiment, obviously." the calm look on Sherlock's face made Marcus want to punch him—more than usual, at any rate.

"My sex life is an experiment?" His jaw clenched.

"Not yours, _Watson's_. I want to see if sex will make her more effective in solving cases, as it does for me. I want you to assist me in finding out."

"Seriously?"

"Seriously."

"And what does Joan think about this?"

"Doesn't know yet." He admitted with a shrug. "But she will. Will you do it?"

"I... I will." Bell blinked, not entirely sure why he had accepted. He knew it was wrong—that Joan didn't even know, hadn't so much as expressed an interest. But Sherlock was good at deducing things; that's why he was at the station so often, after all. It stood to reason that he would be good at deducing interactions between people, and pick up signals. Why would he suggest something like this if he didn't think that there was something there?

"Pick her up at seven," was all Sherlock said before leaving.

So it was that at seven, Marcus Bell found himself walking up to the Brownstone. His car was parked around the corner, and he had hastily planned the date; dinner at a quiet, good Italian joint, then a walk in the park, eventually ending up in his flat for drinks and sex, if Joan was amenable. Of course, he had no way of knowing that she would even go out with him; all he had was Sherlock's word, and that could be changed by Joan.

He suspected that she would be extremely unhappy when she realised Sherlock was going to use her sex life as an experiment. He was also aware of the possibility that she would think he was only going out with her because Sherlock had asked him to, not because he genuinely liked her; which he did. It was nerve wrecking, to the extent that he almost didn't realise that the Brownstone's door was open an inch. When he did, he got a gut feeling that something was wrong, _very_ wrong. Although he wasn't on duty, he carried a small pistol with him.

Gently, he nudged the door wider, and went inside, closing the door behind him. He walked cautiously from room to room, discovering that everything was in order. So much so, that he almost kicked himself. Ms Hudson cleaned today, which explained why the place was spotless, and the door was left open. Evidently she had forgotten to close the door properly behind her. He would inform Sherlock and Joan when they appeared; he didn't think they'd mind if he waited inside.

Putting his pistol away and smiling, he took a deep breath. He was relieved that nothing was wrong. He hummed, to the tune of the song that had last played on the radio. Something about blood. It was cheerful enough. As his mind drifted off into nervous thoughts about the night ahead, he heard screaming.

A woman's screaming. "SHERLOCK!" Detective Bell's heart raced. They were in danger. He rushed up the stairs, the screams getting louder, clearly screams of distress...coming from Joan's room. The open door _had_ meant trouble after all.

"Shit," Bell muttered, pulling his pistol out once more, the happy song he had been humming now replaced by constant screams, Joan's screams. As he got closer to the room, he heard Sherlock grunting: they were in pain!

He flung the door open, and stopped in his tracks, flabbergasted. Sherlock was pinned under Joan, who was riding him rhythmically. Neither had noticed his dramatic entrance, but he took in all of their naked glory; Sherlock was covered in tattoos, and Joan was beautiful, as he had imagined she would be. They were breathing heavily. He could tell that they had been having sex for some time, because they were drenched in sweat and their frantic movements suggested they were close to finishing.

"Joan," Sherlock gasped. "Joan I think I'm—"

"Me too," she moaned.

"OH!" they yelled in unison. Simultaneously, there was a loud thump: Bell had fainted.


	4. Explanations

Disclaimer: Don't own the thing. Anyone fancy reviewing? I need to know if this is okay or bad or whatever. Give me a sign! (Or just a review.)

"What happened?" Bell sat up and stretched. They were now in the living room, by the 'wall of crazy', as Joan had dubbed it, and fully clothed; Joan in Sherlock's t-shirt and a pair of jogging bottoms, Sherlock in only trousers. The two turned and looked at each other. If he didn't remember, what was the point in telling him? Bell's eyes narrowed.

"Oh, wait. I remember. Your door was open, so I thought you were in trouble. But there was no sign of a struggle, so I figured I'd wait down here. Then I heard you screaming, figured there was trouble after all. But I got upstairs and you two were..." he looked away, seemingly unable to finish his sentence.

"Having sex." Sherlock prompted. He looked like he was trying not to laugh. "Watson and I came to an agreement, regarding that experiment I told you about."

"My sex life is not an experiment," Joan muttered. Both men ignored her.

"Terribly sorry I forgot to text you telling you the date was off. I was a bit... busy."

"Do I even want to know how this came about?" Bell sighed.

"It's rather a funny story, actually. Called Watson down to inform her of your date tonight, but she had been in the shower—"

"—for _eight_ minutes."

"Yes, yes. Eight minutes, I know. No need to get your knickers in a twist." He snickered. "Especially since I already did it for you." Joan whacked him on his arm, scowling.

"Shut up and get on with telling Bell what happened."

"If you care so much, why don't you finish telling him?"

"Fine, I will."

"Fine."

"Good!"

Bell cleared his throat. "If you guys need to be alone again, I'll happily leave this time." This time, Joan hit him on the arm.

"Anyway," she glared at Sherlock. "He called me downstairs while I was in the shower. It sounded urgent, so I came down wearing a towel."

"And then you guys... you know?"

"No. Then Sherlock pulled me upstairs and picked out clothes for me for our date, which I didn't agree to or have anything to do with making, by the way."

"It was for your own good! I wanted to see if your deductive powers were heightened after sex, as mine are."

"Yeah, so it was for _your_ own good, _your_ experiment."

"Well you would have had fun, I imagine. Unless Bell here wasn't up to it."

"Hey, hey. I would have been up to it!"

"_Anyway_," Joan crossed her arms. "I yelled at him because he was being unreasonable, and my towel fell down. Then he suggested we try his experiment out together."

"So _then_ you had sex."

"No, I got dressed. I wanted to talk about it first. We decided that nothing between us would change. Then we had sex."

"No," Sherlock said with a grin. "First we indulged in foreplay for a considerable amount of time. Then we had sex." Bell pulled a face.

"Can you two stop talking about having sex with each other? I'm getting visuals I never wanted."

"I've got it!" Joan stood up. "Tina Hex didn't kill her husband. Somebody else did."

"Pray, do tell how you know that?" Sherlock propped his chin on his hand.

"Are you telling me that he was _right_?" Bell asked, incredulous.

"I often am, you know."

"I don't know if it's because of your theory. I do know that I've just noticed something I didn't think was that important before."

"What?" Sherlock asked with a frown. "The Hex case was abominably easy to solve. You can't be telling me I was wrong."

"You're not right about _everything_ you know. It just popped into my mind. It was a small detail, while we went around Tina's house, and her daughter, Dani's."

"What was the detail? Spill."

"I noticed that on the master bedroom's bedside cabinet there was a picture of Dani wearing an impressive dress. It fit perfectly. I only noticed it because I thought I'd seen it before somewhere. I just remembered that my friend was telling me about it about a month ago; it's the most expensive dress in the world. But Dani lived in poverty. And her mother said she didn't plan on sharing any of the inheritance with her. How could Dani have been wearing that dress, and why would Tina Hex have kept it beside her at night, when she claims she hates her youngest child?" Joan spotted Clyde on the floor and picked him up, stroking him gently.

"On top of that, did you notice that Tina's clothes didn't fit her properly? They were too big for her."

"So what?" Bell asked with a shrug. "Perhaps she has a taste for baggy clothing."

"But the clothes were all designed to be form fitting. And Dani's clothes were too small, which at first didn't seem too weird, because she's poor, right? But you know who would fit those clothes pretty well? Tina. The styles were different, too. Tina's clothes were too young, too hip. Dani's were too old."

"What are you getting at, Watson?" Bell frowned.

"I think Watson is suggesting that our billionaire was murdered by his daughter, not his ex-wife, and that Tina Hex is serving time in jail in her stead."

"But why would she agree to that?"

"She may have many reasons. But did you see the state of where 'Dani' was living? It was horrible. I imagine prison would be a step up from that, with constant meals every day and companionship, no matter how criminal. It's very likely that Dani promised her mum when her jail sentence was finished, she would get a slice of the inheritance for serving time. How to prove it though? Hmm. I think security cameras is the best way. That way we can see them putting the house back to normal and see how long Dani has been living there instead of Tina. If that fails, there'll be other ways." Sherlock nodded. "Yes, I think you're right, Watson. And so am I! Once again, we're proven compatible."

Joan blushed, thinking about the last time he had said they were compatible, and the acts which had followed. Bell looked confused once more, but awkwardly got to his feet.

"Well, I'm going to leave you crazy kids here. Some of us need to get some sleep. We've got a murderer to catch out tomorrow." He mockingly bowed to Joan. "Milady." He began walking out, but turned back with a smile. "I'm still available for that date, if you ever want it."


End file.
